I want to make a text converter to unicode converter. The code was going pretty well but I am stuck at changing as '\' is shown invalid

 else if (arr2[i] == ']') {
  mainarr.push('े')
} else if (arr2[i] == '}') {
  mainarr.push('ै')
} else if (arr2[i] == '\') {
  mainarr.push('्')
}

I want to make a text converter to unicode converter. The code was going pretty well but I am stuck at changing as '' is shown invalid. Any way I can type '/' ?